---
title: Cloudflare Workers and Bun.serve
description: Put Agentside in front of a plain fetch handler on Cloudflare Workers or Bun.
---

Any runtime with a `fetch(request)` entry point can wrap its handler in `handle`.

## Cloudflare Workers

With static assets, the Worker has to run before the asset handler so it can negotiate every request. Set `run_worker_first` in your Wrangler config.

```jsonc wrangler.jsonc
{
  "name": "acme",
  "main": "src/worker.ts",
  "assets": { "directory": "./dist", "binding": "ASSETS", "run_worker_first": true }
}
```

```ts src/worker.ts
import { agentside, remote } from "@usenotra/agentside";

const twins = agentside({
  routes: {
    "/": "# Acme\n\nAcme sends invoices your customers actually pay.",
    "/docs/[...path]": remote(({ params }) => `https://cms.acme.dev/docs/${params.path}.md`),
  },
});

export default {
  fetch(request: Request, env: { ASSETS: Fetcher }) {
    return twins.handle(request, () => env.ASSETS.fetch(request));
  },
};
```

Responses from `env.ASSETS.fetch` have immutable headers. Agentside detects that and copies the response before it adds the `Link` and `Vary` headers, so no extra code is needed.

The in-memory cache lives per isolate. Rely on `Cache-Control` for caching across isolates and regions.

## Bun.serve

```ts server.ts
import { agentside } from "@usenotra/agentside";

import { app } from "./app";

const twins = agentside({
  routes: {
    "/": "# Acme\n\nAcme sends invoices your customers actually pay.",
    "/pricing": () => Bun.file("content/pricing.md").text(),
  },
});

Bun.serve({
  port: 3000,
  fetch: (request) => twins.handle(request, () => app(request)),
});
```

`app` is whatever renders your HTML, for example another framework's fetch handler.